Light irradiation system and illumination unit

Abstract

To improve visibility of an irradiation pattern emitted to a road surface.SOLUTION: A light irradiation system includes: an illumination unit (45L) which is configured to irradiate a road surface with a sequential irradiation pattern (P); and a control part which is configured to control the illumination unit (45L) so as to irradiate the road surface with the sequential irradiation pattern (P). The sequential irradiation pattern (P) has: a proximal side irradiation pattern (Pa); and a distal side irradiation pattern (Pc) which is emitted to a position further away from the illumination unit (45L) than the proximal side irradiation pattern (Pa). The distal side irradiation pattern (Pc) is emitted to the road surface after the proximal side irradiation pattern (Pa) is emitted to the road surface. The control part is configured to control the illumination unit (45L) so as to improve visibility of the distal side irradiation pattern (Pc) to a pedestrian H existing in the periphery of the illumination unit (45L).SELECTED DRAWING: Figure 3C

Description

[Technical field]

[0001] The present disclosure relates to a lighting system and a lighting unit. [Background technology]

[0002] Countries around the world are currently considering equipping vehicles with light illumination systems configured to project an illumination pattern onto the road surface around the vehicle in order to provide pedestrians and others around the vehicle with information indicating the vehicle's operation (for example, information indicating whether the vehicle is turning left, right, or reversing) (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 067113 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the visibility of the multiple irradiation patterns projected onto the road surface is low, pedestrians in the blind spots of the vehicle are unlikely to notice the presence of the irradiation patterns. As a result, it is expected that the pedestrians may not be able to clearly recognize the presence or movement of the vehicle. Thus, there is room for further improvement of the light projection system mounted on the vehicle in terms of improving the visibility of the irradiation patterns projected onto the road surface.

[0005] The present disclosure aims to improve the visibility of sequential illumination patterns on objects such as pedestrians. [Means for solving the problem]

[0006] A light irradiation system according to an embodiment of the present disclosure includes: a lighting unit configured to project a sequential illumination pattern onto a road surface; and a control unit configured to control the lighting units so that the sequential illumination pattern is illuminated onto the road surface. The sequential irradiation pattern includes a first irradiation pattern and a second irradiation pattern that is irradiated at a position farther from the lighting unit than the first irradiation pattern. The second irradiation pattern is irradiated onto the road surface after the first irradiation pattern is irradiated onto the road surface. The control unit is configured to control the lighting unit so as to improve visibility of the second irradiation pattern with respect to an object present around the lighting unit.

[0007] According to the above configuration, the lighting unit is controlled so that the visibility of the second irradiation pattern for objects such as pedestrians is improved. As a result, the visibility of the sequential irradiation pattern for pedestrians and the like present around the lighting unit is improved. Therefore, pedestrians and the like can clearly grasp the presence and movement of the vehicle by visually recognizing the sequential irradiation pattern.

[0008] A lighting unit according to one aspect of the disclosure is configured to project a sequential illumination pattern onto a road surface. The sequential irradiation pattern includes a first irradiation pattern and a second irradiation pattern that is irradiated at a position farther from the lighting unit than the first irradiation pattern. The second irradiation pattern is irradiated onto the road surface after the first irradiation pattern is irradiated onto the road surface. The lighting unit is configured to irradiate the sequential irradiation pattern such that visibility of the second irradiation pattern on an object present around the lighting unit is improved.

[0009] According to the above configuration, the visibility of the second irradiation pattern for objects such as pedestrians present around the lighting unit is improved, and therefore the visibility of the sequential irradiation pattern for pedestrians is improved. Therefore, pedestrians can clearly recognize the presence and movement of a vehicle by visually recognizing the sequential irradiation pattern.

[0010] A light irradiation system according to another aspect of the present disclosure includes: a lighting unit configured to project a lighting pattern onto a road surface; and a control unit configured to control the lighting unit so that the illumination pattern is illuminated onto the road surface. The control unit is configured to control the lighting unit so that visibility of the irradiation pattern from a start time when irradiation of the irradiation pattern starts to a predetermined time is higher than visibility of the irradiation pattern from the predetermined time to a stop time when irradiation of the irradiation pattern is stopped.

[0011] According to the above configuration, the visibility of the irradiation pattern during the period from the start time when the irradiation of the irradiation pattern is started to the predetermined time is higher than the visibility of the irradiation pattern during the period from the predetermined time to the stop time when the irradiation of the irradiation pattern is stopped. Therefore, pedestrians and the like can easily notice the existence of the irradiation pattern projected onto the road surface, and the visibility of the irradiation pattern for pedestrians and the like is improved.

[0012] According to another aspect of the present disclosure, a lighting unit is configured to project a light pattern onto a road surface. The lighting unit is configured to project the irradiation pattern onto the road surface so that visibility of the irradiation pattern from a start time when projection of the irradiation pattern begins to a predetermined time is higher than visibility of the irradiation pattern from the predetermined time to a stop time when projection of the irradiation pattern is stopped. Effect of the Invention

[0013] According to the present disclosure, it is possible to improve the visibility of a sequential irradiation pattern for objects such as pedestrians. [Brief description of the drawings]

[0014] [Figure 1] 1 is a front view of a vehicle equipped with a vehicle system according to an embodiment of the present invention (hereinafter simply referred to as the present embodiment). [Diagram 2] 1 is a block diagram of a vehicle system according to an embodiment of the present invention. [Figure 3A] FIG. 13 is a diagram showing a state in which a proximal side irradiation pattern out of the sequential irradiation pattern is irradiated onto a road surface. [Figure 3B] 13 is a diagram showing a state in which a proximal side irradiation pattern and a middle side irradiation pattern among sequential irradiation patterns are irradiated onto a road surface. FIG. [Figure 3C] 13 is a diagram showing a state in which a proximal side irradiation pattern, a middle side irradiation pattern, and a distal side irradiation pattern among sequential irradiation patterns are irradiated onto a road surface. FIG. [Figure 3D] 13 is a diagram showing a state in which irradiation of the proximal side irradiation pattern, the intermediate side irradiation pattern, and the distal side irradiation pattern is stopped. FIG. [Figure 4] FIG. 13 is a timing chart for explaining the irradiation timing of a proximal side irradiation pattern, an intermediate side irradiation pattern, and a distal side irradiation pattern. [Diagram 5] FIG. 13 is a diagram showing a state in which the distal side irradiation pattern projected onto the road surface is vibrating. [Figure 6] FIG. 13 shows a distal illumination pattern composed of multiple rectangular illumination patterns separated from one another. [Figure 7] FIG. 13 is a timing chart for explaining the irradiation timing of a proximal side irradiation pattern, an intermediate side irradiation pattern, and a distal side irradiation pattern. [Figure 8] FIG. 2 is a diagram for explaining an example of a configuration of a lighting unit. [Figure 9A]1 is a conceptual diagram for explaining the change over time in the direct current supplied to the light-emitting element during the time period from the start time when the irradiation of the irradiation pattern starts to the stop time when the irradiation of the irradiation pattern stops. [Figure 9B] 4 is a diagram for explaining a part of the configuration of a current control circuit that supplies a direct current to a light-emitting element. FIG. [Figure 10A] 10 is a conceptual diagram for explaining an example of a pulse current supplied to a light source unit in a time period from a start time when irradiation of an irradiation pattern starts to a stop time when irradiation of the irradiation pattern stops. FIG. [Figure 10B] 13 is a conceptual diagram for explaining another example of a pulse current supplied to a light source unit in a time period from a start time when irradiation of an irradiation pattern starts to a stop time when irradiation of the irradiation pattern stops. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention (hereinafter, referred to as the present embodiment) will be described with reference to the drawings. For the sake of convenience of explanation, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component.

[0016] In addition, in the description of this embodiment, for convenience of explanation, the "left-right direction", "up-down direction", and "front-rear direction" may be referred to as appropriate. These directions are relative directions set for the vehicle 1 shown in FIG. 1. Here, the "left-right direction" is a direction that includes the "left direction" and the "right direction", and is also the vehicle width direction of the vehicle 1. The "up-down direction" is a direction that includes the "upward direction" and the "downward direction". The "front-rear direction" is a direction that includes the "forward direction" and the "rearward direction". Although not shown in FIG. 1, the front-rear direction is a direction that is perpendicular to the left-right direction and the up-down direction.

[0017] First, a vehicle system 2 according to this embodiment will be described below with reference to Figures 1 and 2. Figure 1 is a front view of a vehicle 1 equipped with the vehicle system 2. Figure 2 is a block diagram of the vehicle system 2. The vehicle 1 is, for example, a vehicle (automobile) capable of running in a manual driving mode or an automatic driving mode.

[0018] 2, the vehicle system 2 includes a vehicle control unit 3, a left side light irradiation system 4L (hereinafter simply referred to as the light irradiation system 4L), a right side light irradiation system 4R (hereinafter simply referred to as the light irradiation system 4R), a sensor 5, a camera 6, and a radar 7. Furthermore, the vehicle system 2 includes an HMI (Human Machine Interface) 8, a GPS (Global Positioning System) 9, a wireless communication unit 10, a storage device 11, a steering actuator 12, a steering device 13, a brake actuator 14, a brake device 15, an accelerator actuator 16, and an accelerator device 17.

[0019] The vehicle control unit 3 is configured to control the traveling of the vehicle 1. The vehicle control unit 3 is configured, for example, by at least one electronic control unit (ECU: Electronic Control Unit). The electronic control unit includes a computer system (for example, SoC (System on a Chip) or the like) including one or more processors and one or more memories, and an electronic circuit configured by active elements such as transistors and passive elements. The processor includes, for example, at least one of a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), and a TPU (Tensor Processing Unit). The CPU may be configured by multiple CPU cores. The GPU may be configured by multiple GPU cores. The memory includes a ROM (Read Only Memory) and a RAM (Random Access Memory). A vehicle control program may be stored in the ROM. For example, the vehicle control program may include an artificial intelligence (AI) program for automatic driving. The RAM may temporarily store the vehicle control program, vehicle control data, and / or surrounding environment information indicating the surrounding environment of the vehicle. The processor may be configured to load a specified program from various vehicle control programs stored in the ROM onto the RAM and execute various processes in cooperation with the RAM. The computer system may be configured with a non-von Neumann type computer such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array). The computer system may be configured with a combination of a von Neumann type computer and a non-von Neumann type computer.

[0020] The light irradiation system 4L includes an illumination unit 45L and a control unit 46L. The illumination unit 45L is configured to illuminate a sequential irradiation pattern P (see FIG. 3C) on the road surface around the vehicle 1 so as to present information indicating the operation of the vehicle 1 to the outside of the vehicle 1. The information indicating the operation of the vehicle 1 is, for example, information indicating a left turn of the vehicle 1. For example, when a left turn of the vehicle 1 is determined, the illumination unit 45L illuminates the sequential irradiation pattern P on the road surface to present the left turn of the vehicle 1 to the outside. In the sequential irradiation pattern P, the irradiation pattern illuminated on the road surface changes continuously as time passes. A specific example of the sequential irradiation pattern P will be described later.

[0021] The location, drawing method, and configuration of the lighting unit 45L are not particularly limited. For example, as shown in FIG. 1, the lighting unit 45L may be disposed in the lamp chamber of the left headlamp 20L. The lighting unit 45L may also be disposed on the roof 100A. The projection method or the scan method may be adopted as the drawing method of the lighting unit 45L. The lighting unit 45L may be configured by a light source unit configured to emit light, and an optical system configured to form a sequential irradiation pattern P based on the light emitted from the light source unit and then irradiate the sequential irradiation pattern P toward the road surface. The light source unit may be configured by, for example, a plurality of LED (Light Emitting Diode) elements or LD (Laser Diode) elements. The optical system may be configured by, for example, a projection lens and / or a reflector configured to control the deflection of the light emitted from the light source unit.

[0022] Furthermore, the lighting unit 45L may be configured with a light source unit that emits light, a driving mirror, and an optical system such as lenses and mirrors. The driving mirror is configured to form a sequential irradiation pattern P that is irradiated onto the road surface based on the light emitted from the light source unit. The driving mirror may be configured with, for example, a MEMS (Micro Electro Mechanical Systems) mirror, a DMD (Digital Mirror Device), or a blade mirror. For example, the light emitted from the light source unit may be scanned onto the road surface by the MEMS mirror. In this way, the irradiation pattern may be projected onto the road surface by the scanning of light by the MEMS mirror.

[0023] The control unit 46L is configured to control the lighting unit 45L so that the sequential irradiation pattern P is irradiated onto the road surface around the vehicle 1. The location of the control unit 46L is not particularly limited. The control unit 46L includes a microcontroller and an analog drive control circuit. The microcontroller includes a processor such as a CPU and a memory such as a ROM. The analog drive control circuit includes a current control circuit configured to control the current supplied to the light source unit and / or a mirror drive circuit configured to control the drive mirror. In this regard, when the lighting unit 45L does not include a drive mirror, the analog drive control circuit is configured by the current control circuit.

[0024] For example, when the vehicle control unit 3 determines that the vehicle 1 turns left or when the driver operates the turn signal lever to determine that the vehicle turns left, the vehicle control unit 3 transmits an instruction signal to the control unit 46L to instruct the control unit 46L to emit the sequential irradiation pattern P. After that, the control unit 46L controls the driving of the lighting unit 45L so that the sequential irradiation pattern P is emitted onto the road surface based on the instruction signal transmitted from the vehicle control unit 3. In this embodiment, the control unit 46L may be separated from the vehicle control unit 3 or may be configured integrally with the vehicle control unit 3.

[0025] The light irradiation system 4R has the same configuration as the light irradiation system 4L described above. The light irradiation system 4R has a lighting unit 45R and a control unit 46R. The lighting unit 45R is configured to project a sequential irradiation pattern onto the road surface around the vehicle 1 so as to present information indicating the operation of the vehicle 1 to the outside of the vehicle 1. The information indicating the operation of the vehicle 1 is, for example, information indicating a right turn of the vehicle 1. For example, when a right turn of the vehicle 1 is determined, the lighting unit 45R projects a sequential irradiation pattern onto the road surface to present the right turn of the vehicle 1 to the outside. The characteristics of the sequential irradiation pattern emitted from the lighting unit 45R are basically the same as the characteristics of the sequential irradiation pattern P emitted from the lighting unit 45L.

[0026] The location, drawing method, and configuration of the lighting unit 45R are not particularly limited. For example, as shown in Fig. 1, the lighting unit 45R may be disposed in the lamp chamber of the right headlamp 20R. The lighting unit 45R may also be disposed on the roof 100A.

[0027] In this embodiment, for convenience of explanation, the light irradiation systems 4L, 4R arranged on the front side of the vehicle 1 are described, but the light irradiation systems may also be arranged on the rear side of the vehicle 1. In this case, as shown in FIG. 3A, the lighting unit 30L of the left rear light irradiation system may be arranged in the lamp chamber of the left rear combination lamp 60L of the vehicle 1. The lighting unit 30R of the right rear light irradiation system may be arranged in the lamp chamber of the right rear combination lamp 60R of the vehicle 1. The lighting units 30L, 30R are configured to project sequential irradiation patterns onto the road surface in order to present information indicating that the vehicle 1 is moving backward toward the outside of the vehicle 1.

[0028] Returning to Fig. 2, the sensor 5 includes at least one of an acceleration sensor, a speed sensor, and a gyro sensor. The sensor 5 is configured to detect the driving state of the vehicle 1 and output driving state information to the vehicle control unit 3. The sensor 5 may further include a seating sensor that detects whether the driver is sitting in the driver's seat, a face direction sensor that detects the direction of the driver's face, an external weather sensor that detects the external weather conditions, and a human presence sensor that detects whether a person is inside the vehicle.

[0029] The camera 6 is a camera including an imaging element such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). The camera 6 is configured to obtain image data showing the surrounding environment of the vehicle 1 and transmit the image data to the vehicle control unit 3. The vehicle control unit 3 obtains surrounding environment information based on the transmitted image data. Here, the surrounding environment information may include information on objects (pedestrians, other vehicles, signs, etc.) present outside the vehicle 1. For example, the surrounding environment information may include information on attributes of objects present outside the vehicle 1 and information on the distance and position of the objects relative to the vehicle 1.

[0030] The radar 7 includes at least one of a millimeter wave radar, a microwave radar, and a LiDAR unit. For example, the LiDAR unit is configured to detect the surrounding environment of the vehicle 1. In particular, the LiDAR unit is configured to obtain point cloud data indicating the surrounding environment of the vehicle 1 and then transmit the point cloud data to the vehicle control unit 3. The vehicle control unit 3 identifies surrounding environment information based on the transmitted point cloud data.

[0031] The HMI 8 is composed of an input unit that accepts input operations from the driver, and an output unit that outputs driving information of the vehicle 1, etc. to the driver. The input unit includes a steering wheel, an accelerator pedal, a brake pedal, a driving mode changeover switch that changes the driving mode of the vehicle 1, etc. The output unit is a display device (e.g., HUD, etc.) that displays various driving information. The HUD is configured to display the driving information of the vehicle 1 on the front window 60. The GPS 9 is configured to acquire current position information of the vehicle 1, and output the acquired current position information to the vehicle control unit 3.

[0032] The wireless communication unit 10 is configured to receive information (e.g., travel information, etc.) about other vehicles around the vehicle 1 from the other vehicles and transmit information (e.g., travel information, etc.) about the vehicle 1 to the other vehicles (vehicle-to-vehicle communication). The wireless communication unit 10 is also configured to receive infrastructure information from infrastructure equipment such as traffic lights and marker lights and transmit travel information of the vehicle 1 to the infrastructure equipment (road-to-vehicle communication). The wireless communication unit 10 is also configured to receive information about pedestrians from portable electronic devices (smartphones, tablets, wearable devices, etc.) carried by pedestrians and transmit vehicle travel information of the vehicle 1 to the portable electronic device (pedestrian-to-vehicle communication). The vehicle 1 may directly communicate with other vehicles, infrastructure equipment, or portable electronic devices in an ad-hoc mode, or may communicate via an access point. The vehicle 1 may also communicate with other vehicles, infrastructure equipment, or portable electronic devices via a communication network such as the Internet.

[0033] The storage device 11 is an external storage device such as a hard disk drive (HDD) or a solid state drive (SSD). Two-dimensional or three-dimensional map information and / or a vehicle control program may be stored in the storage device 11. For example, the three-dimensional map information may be composed of point cloud data. The storage device 11 is configured to output the map information and the vehicle control program to the vehicle control device 3 in response to a request from the vehicle control device 3. The map information and the vehicle control program may be updated via the wireless communication unit 10 and a communication network.

[0034] When the vehicle 1 runs in the autonomous driving mode, the vehicle control unit 3 automatically generates at least one of a steering control signal, an accelerator control signal, and a brake control signal based on the running state information, the surrounding environment information, the current position information, the map information, etc. The steering actuator 12 is configured to receive the steering control signal from the vehicle control unit 3 and control the steering device 13 based on the received steering control signal. The brake actuator 14 is configured to receive the brake control signal from the vehicle control unit 3 and control the brake device 15 based on the received brake control signal. The accelerator actuator 16 is configured to receive the accelerator control signal from the vehicle control unit 3 and control the accelerator device 17 based on the received accelerator control signal.

[0035] On the other hand, when the vehicle 1 runs in the manual driving mode, the vehicle control unit 3 generates a steering control signal, an accelerator control signal, and a brake control signal in accordance with the driver's manual operation of the accelerator pedal, the brake pedal, and the steering wheel. In this way, in the manual driving mode, the steering control signal, the accelerator control signal, and the brake control signal are generated by the driver's manual operation, so that the running of the vehicle 1 is controlled by the driver.

[0036] Next, the sequential irradiation pattern P emitted from the lighting unit 45L will be described in detail below with reference to Figs. 3A to 4. Fig. 3A is a diagram showing a state in which the proximal side irradiation pattern Pa (an example of a first irradiation pattern) of the sequential irradiation pattern P is irradiated onto the road surface. Fig. 3B is a diagram showing a state in which the proximal side irradiation pattern Pa and the intermediate side irradiation pattern Pb (an example of a third irradiation pattern) of the sequential irradiation pattern P are irradiated onto the road surface. Fig. 3C is a diagram showing a state in which the proximal side irradiation pattern Pa, the intermediate side irradiation pattern Pb and the distal side irradiation pattern Pc (an example of a second irradiation pattern) of the sequential irradiation pattern P are irradiated onto the road surface. Fig. 3D is a diagram showing a state in which the irradiation of the proximal side irradiation pattern Pa, the intermediate side irradiation pattern Pb and the distal side irradiation pattern Pc is stopped. Fig. 4 is a diagram showing a timing chart for explaining the irradiation timing of the proximal side irradiation pattern Pa, the intermediate side irradiation pattern Pb and the distal side irradiation pattern Pc. In the following description, for convenience of explanation, the proximal side irradiation pattern Pa, the intermediate side irradiation pattern Pb, and the distal side irradiation pattern Pc may be referred to as the irradiation patterns Pa, Pb, and Pc, respectively.

[0037] In addition, as shown in Fig. 8, in the following description, it is assumed that the projection method is adopted as the drawing method of the lighting unit 45L. As shown in Fig. 8, the lighting unit 45L has a light source section 120 and a projection lens 125 configured to irradiate a sequential irradiation pattern P toward a road surface based on the light emitted from the light source section 120. The light source section 120 has light emitting elements 121 to 123 and a submount substrate 124 on which the light emitting elements 121 to 123 are mounted. The light emitting elements 121 to 123 are configured of, for example, LEDs.

[0038] The projection lens 125 is configured to form an irradiation pattern Pa on the road surface S based on the light emitted from the light emitting element 121. The projection lens 125 is also configured to form an irradiation pattern Pb on the road surface S based on the light emitted from the light emitting element 122. The projection lens 125 is also configured to form an irradiation pattern Pc on the road surface S based on the light emitted from the light emitting element 123. The brightness (illuminance) of the irradiation patterns Pa to Pc projected onto the road surface S increases in the order of Pa>Pb>Pc. In other words, the farther the irradiation pattern is from the vehicle 1, the lower the brightness of the irradiation pattern.

[0039] The control unit 46L includes a microcontroller 43L and a current control circuit 42L. The microcontroller 43L is configured to transmit a predetermined control signal to the current control circuit 42L in response to receiving an instruction signal from the vehicle control unit 3. The current control circuit 42L is configured to control a current supplied to each of the light emitting elements 121-123 of the light source unit 120. The current control circuit 42L may supply a direct current to each of the light emitting elements 121-123 and adjust the value of the direct current supplied to each of the light emitting elements. The current control circuit 42L may supply a pulse current to each of the light emitting elements 121-123 and adjust the value and DUTY ratio of the pulse current supplied to each of the light emitting elements. Here, in the pulse current, a pulse of ON time (High state) and a pulse of OFF time (Low state) are successive in a predetermined cycle. The DUTY ratio is a ratio % of the ON time of the pulse to the cycle of the pulse current.

[0040] In this embodiment, when the current control circuit 42L supplies a direct current to each of the light emitting elements 121-123, the current control circuit 42L may include a power supply circuit such as a DC / DC converter and a peaking circuit shown in Fig. 9B (this will be described later). When the current control circuit 42L supplies a pulse current to each of the light emitting elements 121-123, the current control circuit 42L may include a power supply circuit such as a DC / DC converter and a PWM control circuit.

[0041] When it is determined that the vehicle 1 will turn left, the control unit 46L controls the driving of the lighting unit 45L so that a sequential irradiation pattern P is irradiated onto the road surface based on an instruction signal transmitted from the vehicle control unit 3. As shown in FIG. 3C, the sequential irradiation pattern P has a proximal side irradiation pattern Pa, a middle side irradiation pattern Pb, and a distal side irradiation pattern Pc.

[0042] When the sequential irradiation pattern P is irradiated onto the road surface, first, the lighting unit 45L irradiates the proximal side irradiation pattern Pa onto the road surface ahead of the vehicle 1 (see FIG. 3A). Next, as shown in FIG. 3B, the lighting unit 45L irradiates the intermediate side irradiation pattern Pb at a position farther from the vehicle 1 (lighting unit 45L) than the proximal side irradiation pattern Pa while maintaining the irradiation of the proximal side irradiation pattern Pa. In the state shown in FIG. 3B, the proximal side irradiation pattern Pa and the intermediate side irradiation pattern Pb irradiated onto the road surface are aligned in the D1 direction. The D1 direction is the extension direction of the sequential irradiation pattern P.

[0043] Next, as shown in Fig. 3C, the lighting unit 45L irradiates the distal side irradiation pattern Pc at a position farther from the vehicle 1 (lighting unit 45L) than the intermediate side irradiation pattern Pb while maintaining the irradiation of the proximal side irradiation pattern Pa and the intermediate side irradiation pattern Pb. In the state shown in Fig. 3C, the proximal side irradiation pattern Pa, the intermediate side irradiation pattern Pb, and the distal side irradiation pattern Pc irradiated on the road surface are aligned in the D1 direction.

[0044] Although the shape of the irradiation patterns Pa to Pc is rectangular, the shape of the irradiation patterns Pa to Pc is not particularly limited. In addition, in the example of Fig. 3C, the irradiation patterns Pa to Pc are separated from each other, but the irradiation patterns Pa to Pc may be in contact with each other.

[0045] Next, as shown in FIG. 3D, the lighting unit 45L stops the irradiation of the irradiation patterns Pa to Pc. In the sequential irradiation pattern P in which the irradiation pattern changes continuously with time, the irradiation patterns Pa to Pc are sequentially irradiated onto the road surface in one period Ts of the sequential irradiation pattern P, and then the irradiation of all of the irradiation patterns Pa to Pc is stopped. The period Ts of the sequential irradiation pattern P is, for example, within a range of 100 ms to 500 ms. That is, the number of irradiations of the sequential irradiation pattern P in one minute is, for example, within a range of 60 times to 600 times. In particular, the period Ts of the sequential irradiation pattern P may be the same as the sequential lighting period of the sequential turn lamp.

[0046] As shown in FIG. 4, when the irradiation time when only the irradiation pattern Pa is irradiated onto the road surface is Ta, the irradiation time when the two irradiation patterns Pa and Pb are irradiated onto the road surface is Tb, the irradiation time when all of the irradiation patterns Pa to Pc are irradiated onto the road surface is Tc, and the stop time when all of the irradiation patterns Pa to Pc are stopped is Toff, one period Ts of the sequential irradiation pattern P is Ts=Ta+Tb+Tc+Toff.

[0047] In addition, the brightness (illuminance) of the irradiation pattern Pc irradiated to the position farthest from the lighting unit 45L is lower than the brightness (illuminance) of the irradiation pattern Pa irradiated to the position closest to the lighting unit 45L. Therefore, the visibility of the irradiation pattern Pc for a pedestrian H (see FIG. 3C, etc.) present around the vehicle 1 tends to be relatively low compared to the visibility of the irradiation pattern Pa. Therefore, the pedestrian H present in the blind spot of the vehicle 1 is less likely to notice the presence of the sequential irradiation pattern P, and is less likely to notice the presence of the vehicle 1.

[0048] On the other hand, in this embodiment, the control unit 46L is configured to control the lighting unit 45L so that the visibility of the irradiation pattern Pc is improved. Specifically, the control unit 46L controls the lighting unit 45L so that the irradiation time Tc during which the irradiation pattern Pc is irradiated is longer than the irradiation times Ta and Tb. In this way, since the irradiation time Tc is set to be longer than the irradiation times Ta and Tb, the visibility of the irradiation pattern Pc to the pedestrian H present around the vehicle 1 is improved, and the visibility of the sequential irradiation pattern P to the pedestrian H is improved. As a result, the pedestrian H can clearly grasp the presence and movement of the vehicle 1 through the sequential irradiation pattern P.

[0049] In addition, in the timing chart shown in FIG. 4, Tc>Toff>Ta=Tb. In particular, each irradiation time and stop time are set so that Ta+Tb+Tc=3Ts / 4 and Toff=Ts / 4. In this respect, in a normally assumed sequential irradiation pattern, Ta=Tb=Tc=Toff=Ts / 4, but in this embodiment, each of the irradiation times Ta and Tb is set to be smaller than Ts / 4 and the irradiation time Tc is set to be larger than Ts / 4. In this way, it is possible to improve the visibility of the irradiation pattern Pc relative to the visibility of the irradiation patterns Pa and Pb.

[0050] (Second method for improving the visibility of the sequential irradiation pattern Pc) Next, a second method for improving the visibility of the irradiation pattern Pc will be described below with reference to Fig. 5. Fig. 5 is a diagram showing a state in which the distal side irradiation pattern Pc projected onto the road surface is vibrating. As shown in Fig. 5, the control unit 46L may control the lighting unit 45L so that the irradiation pattern Pc vibrates in a D2 direction perpendicular to the D1 direction.

[0051] For example, the control unit 46L may vibrate the irradiation pattern Pc in the D2 direction by physically vibrating the housing constituting the lighting unit 45L. In addition, when a scanning method is adopted as the drawing method of the lighting unit 45L, the control unit 46L may control the driving of the drive mirror provided in the lighting unit 45L so that the irradiation pattern Pc vibrates in the D2 direction. The vibration frequency of the irradiation pattern Pc may be, for example, within a range of 5 Hz to 10 Hz. In this regard, when the vibration frequency is set within a range of 5 Hz to 10 Hz, the vibrating irradiation pattern Pc is more likely to attract people's attention, and the visibility of the irradiation pattern Pc can be further improved. In addition, by making the irradiation time Tc longer than the irradiation times Ta and Tc and vibrating the irradiation pattern Pc, the visibility of the irradiation pattern Pc for the pedestrian H can be further improved. In this way, the visibility of the sequential irradiation pattern P can be improved by improving the visibility of the irradiation pattern Pc. As a result, the pedestrian H can clearly grasp the presence and operation of the vehicle 1 through the sequential irradiation pattern P.

[0052] In this example, the irradiation pattern Pc vibrates in the D2 direction, but the irradiation pattern Pc may vibrate in the D1 direction. In this way, the direction in which the irradiation pattern Pc vibrates is not particularly limited. In addition, when the irradiation pattern Pc vibrates, the irradiation time Tc does not have to be set longer than the irradiation times Ta and Tb.

[0053] (Third method for improving the visibility of the sequential irradiation pattern Pc) Next, a third method for improving the visibility of the irradiation pattern Pc will be described below with reference to FIG. 6. FIG. 6 is a diagram showing a distal side irradiation pattern Pc composed of a plurality of mutually separated rectangular irradiation patterns Pc1 to Pc3. As shown in FIG. 6, the shape of the irradiation pattern Pc is different from the shapes of the irradiation patterns Pa and Pb. In particular, each of the irradiation patterns Pa and Pb is composed of a single rectangular irradiation pattern, while the irradiation pattern Pc is composed of three rectangular irradiation patterns Pc1 to Pc3. The irradiation patterns Pc1 to Pc3 are aligned in the D1 direction and are separated from each other.

[0054] The control unit 46L may control the driving of the lighting unit 45L so that the irradiation patterns Pa and Pb are configured by a single rectangular irradiation pattern and the irradiation pattern Pc is configured by a plurality of irradiation patterns Pc1 to Pc3. Since the irradiation pattern Pc is configured by a plurality of irradiation patterns Pc1 to Pc3, the visibility of the pedestrian H for the irradiation pattern Pc is improved. As a result, the visibility of the sequential irradiation pattern P is improved, so that the pedestrian H can clearly recognize the presence and movement of the vehicle 1 through the sequential irradiation pattern P.

[0055] In this example, the irradiation patterns Pc1 to Pc3 may be irradiated on the road surface at the same timing, or may be irradiated on the road surface at different timings. For example, the irradiation patterns Pc1 to Pc3 may be irradiated on the road surface in sequence as a sequential irradiation pattern. When the irradiation patterns Pc1 to Pc3 are irradiated on the road surface in sequence as a sequential irradiation pattern, it is possible to further improve the visibility of the irradiation pattern Pc. Furthermore, when the irradiation pattern Pc is composed of a plurality of irradiation patterns Pc1 to Pc3, the irradiation pattern Pc may be vibrated while adjusting the irradiation time Tc. In this case as well, it is possible to further improve the visibility of the irradiation pattern Pc. On the other hand, when the irradiation pattern Pc is composed of a plurality of irradiation patterns Pc1 to Pc3, the irradiation time Tc may not be longer than the irradiation times Ta and Tb, and the irradiation pattern Pc may not be vibrated.

[0056] (Fourth method for improving the visibility of the sequential irradiation pattern Pc) Next, a fourth method for improving the visibility of the sequential irradiation pattern Pc will be described below with reference to Fig. 7 to Fig. 10B. Similarly in this example, the lighting unit 45L mounted on the vehicle 1 irradiates the sequential irradiation pattern P shown in Figs. 3A to 3D onto the road surface. Fig. 7 is a timing chart for explaining the irradiation timing of the proximal side irradiation pattern Pa, the intermediate side irradiation pattern Pb, and the distal side irradiation pattern Pc among the sequential irradiation pattern P.

[0057] As shown in FIG. 7, when the irradiation time when only the irradiation pattern Pa is irradiated onto the road surface is Ta, the irradiation time when the two irradiation patterns Pa and Pb are irradiated onto the road surface is Tb, the irradiation time when all of the irradiation patterns Pa to Pc are irradiated onto the road surface is Tc, and the stop time when all of the irradiation patterns Pa to Pc are stopped is Toff, one period Ts of the sequential irradiation pattern P is Ts=Ta+Tb+Tc+Toff.

[0058] The irradiation time Ta is defined by the start time t1 when irradiation of the irradiation pattern Pa starts and the start time t2 when irradiation of the irradiation pattern Pb starts. The irradiation time Tb is defined by the start time t2 and the start time t3 when irradiation of the irradiation pattern Pc starts. The irradiation time Tc is defined by the start time t3 and the stop time t4 when the irradiation of the irradiation patterns Pa, Pb, and Pc stops.

[0059] In the irradiation pattern Pa, the visibility of the irradiation pattern Pa from the start time t1 to the predetermined time tn is higher than the visibility of the irradiation pattern Pa from the predetermined time tn to the stop time t4. Similarly, in the irradiation pattern Pb, the visibility of the irradiation pattern Pb from the start time t2 to the predetermined time tn is higher than the visibility of the irradiation pattern Pb from the predetermined time tn to the stop time t4. In the irradiation pattern Pc, the visibility of the irradiation pattern Pc from the start time t3 to the predetermined time tn is higher than the visibility of the irradiation pattern Pc from the predetermined time tn to the stop time t4. The time period ΔT between the start times t1, t2, t3 and the predetermined time tn is, for example, within a range of 1 ms to 200 ms.

[0060] In this regard, the longer the time period ΔT, the higher the visibility of the irradiation pattern, but the greater the power consumption consumed by the light source section 120 of the lighting unit 45L. On the other hand, the shorter the time period ΔT, the lower the visibility of the irradiation pattern, but the smaller the power consumption consumed by the light source section 120. In this embodiment, the predetermined time period ΔT is set by focusing on two factors, the visibility of the irradiation pattern and the power consumption of the light source section 120.

[0061] Next, referring to Fig. 9A to Fig. 10B, a method for improving the visibility of the irradiation pattern in a time period ΔT between the start time when the irradiation of the irradiation pattern starts and the predetermined time tn will be described below. In this example, a method for improving the visibility of the irradiation pattern Pc in a time period ΔT between the start time t3 and the predetermined time tn will be described. The method for improving the visibility of the irradiation patterns Pa and Pb in the time period ΔT is the same as the method for improving the visibility of the irradiation pattern Pc in the time period ΔT, so the description thereof will be omitted in this specification.

[0062] (When the current supplied to each light-emitting element is a direct current) First, with reference to FIGS. 9A and 9B, a method for improving the visibility of the irradiation pattern Pc in the time period ΔT between the start time t3 and the predetermined time tn when the current supplied to the light-emitting element 123 of the light source unit 120 is a direct current will be described. FIG. 9A is a conceptual diagram for explaining the temporal change of the direct current supplied to the light-emitting element 123 in the time period from the start time t3 when the irradiation of the irradiation pattern Pc starts to the stop time t4 when the irradiation of the irradiation pattern Pc stops. FIG. 9B is a diagram for explaining a part of the configuration of the current control circuit 42L that supplies a direct current to the light-emitting element 123.

[0063] As shown in FIG. 9A, the control unit 46L adjusts the current supplied to the light-emitting element 123 so that the visibility of the irradiation pattern Pc between the start time t3 and the predetermined time tn is higher than the visibility of the irradiation pattern Pc between the predetermined time tn and the stop time t4. Specifically, the control unit 46L adjusts the current supplied to the light-emitting element 123 so that the brightness (illuminance) of the irradiation pattern Pc between the start time t3 and the predetermined time tn is greater than the brightness (illuminance) of the irradiation pattern Pc between the predetermined time tn and the stop time t4. More specifically, the control unit 46L adjusts the direct current supplied to the light-emitting element 123 so that the value of the direct current supplied to the light-emitting element 123 between the start time t3 and the predetermined time tn is greater than the value of the direct current supplied to the light-emitting element 123 between the predetermined time tn and the stop time t4.

[0064] That is, the control unit 46L is configured to increase the value of the direct current supplied to the light-emitting element 123 in the time period ΔT in order to improve the visibility of the irradiation pattern Pc in the time period ΔT. As shown in FIG. 9A, the current control circuit 42L increases the brightness of the irradiation pattern Pc in the time period ΔT by instantaneously supplying a large direct current to the light-emitting element 123 in the time period ΔT. In this way, it becomes possible to increase the visibility of the irradiation pattern Pc in the time period ΔT. The peak current value I2 in the time period ΔT may be N times (1 < N < 5) larger than the current value I1 in the steady state.

[0065] In order to generate the peak current value I2 in the time period ΔT, the current control circuit 42L may include a peaking circuit composed of a resistor and a capacitor (see FIG. 9B). As shown in FIG. 9B, the resistor R1 determines the current value I1 supplied to the light emitting element 123. Meanwhile, the resistor R2 determines the peak current value I2, and the capacitance of the capacitor C1 determines the width (attenuation time) of the peak waveform related to the peak current value I2. When the resistor R2 is small, the peak current value I2 increases, while when the resistor R2 is large, the peak current value I2 decreases. Also, when the capacitance of the capacitor C1 is small, the width of the peak waveform decreases, while when the capacitance is large, the width of the peak waveform increases. In this way, by adjusting the values ​​of each element, it is possible to set an optimal current waveform in the time period ΔT.

[0066] According to this example, since a large DC current is instantaneously supplied to the light emitting element 123 in the time period ΔT, the brightness of the irradiation pattern Pc in the time period ΔT increases. In this way, the pedestrian H present around the vehicle 1 is more likely to notice the presence of the irradiation pattern Pc irradiated onto the road surface, and the visibility of the irradiation pattern Pc for the pedestrian H is improved. As a result, the pedestrian H can clearly grasp the presence and movement of the vehicle 1 through the sequential irradiation pattern P.

[0067] (When the current supplied to each light-emitting element is a pulse current) Next, a method for improving the visibility of the irradiation pattern Pc in a time period ΔT between a start time t3 and a predetermined time tn when the current supplied to the light emitting element 123 of the light source unit 120 is a pulse current will be described with reference to Fig. 10A and Fig. 10B. Fig. 10A is a conceptual diagram for explaining an example of a pulse current supplied to the light emitting element 123 in a time period from a start time t3 to a stop time t4. Fig. 10B is a conceptual diagram for explaining another example of a pulse current supplied to the light emitting element 123 in a time period from a start time t3 to a stop time t4.

[0068] As described above, when a pulse current is supplied to the light-emitting element 123, the current control circuit 42L of the control unit 46L may include a DC / DC converter (for example, a switching regulator or the like) and a PWM control circuit.

[0069] First, an example in which a pulse current as shown in FIG. 10A is supplied to the light-emitting element 123 will be described below. As shown in FIG. 10A, the control unit 46L is configured to increase the value I4 of the pulse current supplied to the light-emitting element 123 in the time period ΔT from the start time t3 to the predetermined time tn in order to improve the visibility of the irradiation pattern Pc in the time period ΔT. Specifically, the current control circuit 42L is configured to adjust the pulse current so that the value I4 of the pulse current supplied to the light-emitting element 123 in the time period ΔT is larger than the value I3 of the pulse current supplied to the light-emitting element 123 between the predetermined time tn and the stop time t4. Here, the value I4 of the pulse current in the time period ΔT may be N times (1 < N < 5) the value I3 of the pulse current between the predetermined time tn and the stop time t4. On the other hand, the duty ratio of the pulse current in the time period ΔT is the same as the duty ratio of the pulse current between the predetermined time tn and the stop time t4. In this case, the duty ratio is, for example, 50%.

[0070] Thus, since the brightness (illuminance) of the irradiation pattern Pc in the time period ΔT is higher than the brightness (illuminance) of the irradiation pattern Pc between the predetermined time tn and the stop time t4, the visibility of the irradiation pattern Pc in the time period ΔT is higher than the visibility of the irradiation pattern Pc between the predetermined time tn and the stop time t4.

[0071] 10A, the value of the pulse current supplied to the light-emitting element 123 in the time period ΔT increases, and therefore the brightness of the irradiation pattern Pc in the time period ΔT increases. In this way, the pedestrian H around the vehicle 1 is more likely to notice the presence of the irradiation pattern Pc irradiated onto the road surface, and the visibility of the irradiation pattern Pc for the pedestrian H is improved. As a result, the pedestrian H can clearly grasp the presence and movement of the vehicle 1 through the sequential irradiation pattern P.

[0072] Next, an example in which a pulse current as shown in FIG. 10B is supplied to the light-emitting element 123 will be described below. As shown in FIG. 10B, the control unit 46L is configured to increase the value I4 of the pulse current supplied to the light-emitting element 123 in the time period ΔT from the start time t3 to the predetermined time tn, while decreasing the DUTY ratio of the pulse current, in order to improve the visibility of the irradiation pattern Pc in the time period ΔT from the start time t3 to the predetermined time tn. Specifically, the current control circuit 42L is configured to adjust the pulse current so that the value I4 of the pulse current supplied to the light-emitting element 123 in the time period ΔT is greater than the value I3 of the pulse current supplied to the light-emitting element 123 from the predetermined time tn to the stop time t4. Furthermore, the current control circuit 42L is configured to adjust the pulse current so that the DUTY ratio of the pulse current supplied to the light-emitting element 123 in the time period ΔT is smaller than the DUTY ratio of the pulse current supplied to the light-emitting element 123 from the predetermined time tn to the stop time t4.

[0073] The value I4 of the pulsed current in the time period ΔT may be N times (1 < N < 5) the value I3 of the pulsed current from the predetermined time tn to the stop time t4. On the other hand, the duty ratio of the pulsed current in the time period ΔT may be 1 / N times the duty ratio of the pulsed current from the predetermined time tn to the stop time t4. In this case, the value calculated by (the value of the pulsed current) × (the duty ratio) in the time period ΔT is the same as the value calculated by (the value of the pulsed current) × (the duty ratio) from the predetermined time tn to the stop time t4. Therefore, the effective brightness of the irradiation pattern Pc in the time period ΔT is the same as the effective brightness of the irradiation pattern P from the predetermined time tn to the stop time t4.

[0074] For example, when the value I4 of the pulsed current is 2.5 times the value I3 of the pulsed current, the duty ratio of the pulsed current in the time period ΔT may be 20%, while the duty ratio of the pulsed current from the predetermined time tn to the stop time t4 may be 50%.

[0075] Also, it is experimentally known that the higher the instantaneous light intensity of the irradiation pattern, the higher the visibility of the irradiation pattern to the human eye, and the longer the blinking period of the irradiation pattern, the higher the visibility of the irradiation pattern to the human eye. Therefore, in this example, in the time period ΔT, while increasing the value of the pulsed current, the duty ratio of the pulsed current is decreased.

[0076] In this way, while maintaining the effective brightness of the irradiation pattern Pc from the start time t3 to the stop time t4 substantially constant, the visibility of the irradiation pattern Pc in the time period ΔT from the start time t3 to the predetermined time tn can be made higher than the visibility of the irradiation pattern Pc from the predetermined time tn to the stop time t4. Therefore, the pedestrian H existing around the vehicle 1 is more likely to notice the presence of the irradiation pattern Pc irradiated on the road surface, so the visibility of the irradiation pattern Pc to the pedestrian H is improved. As a result, the pedestrian H can clearly grasp the presence and operation of the vehicle 1 through the sequential irradiation pattern P.

[0077] Although the embodiment of the present invention has been described above, it goes without saying that the technical scope of the present invention should not be interpreted as being limited by the description of the embodiment. The embodiment is merely an example, and it is understood by those skilled in the art that various modifications of the embodiment are possible within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and its equivalents.

[0078] For example, in this embodiment, as an example of the operation of the vehicle 1, the sequential irradiation pattern P that is irradiated onto the road surface when the vehicle 1 turns left is mainly described. On the other hand, it should be noted that the sequential irradiation pattern that is irradiated onto the road surface when the vehicle 1 performs other operations (such as turning right, moving forward, and moving backward) has the same characteristics as the sequential irradiation pattern P. That is, even during other operations of the vehicle 1, a sequential irradiation pattern with improved visibility of the distal side irradiation pattern is irradiated onto the road surface. Furthermore, even during other operations of the vehicle 1, the visibility of each irradiation pattern is improved in the time period ΔT between the start of irradiation and the predetermined time tn.

[0079] In addition, in this embodiment, the light irradiation system is provided in the vehicle 1, but the light irradiation system may be provided in equipment other than the vehicle 1 (for example, traffic infrastructure equipment such as traffic signals and street lights).

[0080] This application incorporates by reference the contents disclosed in a Japanese patent application filed on December 25, 2020 (Patent Application No. 2020-217242) and the contents disclosed in a Japanese patent application filed on December 25, 2020 (Patent Application No. 2020-217243).

Claims

1. a lighting unit configured to project a lighting pattern onto a road surface; a control unit configured to control the lighting units so that the illumination pattern is illuminated onto the road surface; the control unit is configured to control the lighting unit so that visibility of the irradiation pattern from a start time when irradiation of the irradiation pattern is started to a predetermined time is higher than visibility of the irradiation pattern from the predetermined time to a stop time when irradiation of the irradiation pattern is stopped.

2. The illumination unit includes a light source configured to emit light that forms the irradiation pattern, 2. The light irradiation system according to claim 1, wherein the control unit is configured to adjust a current supplied to the light source unit so that visibility of the irradiation pattern from the start time to the specified time is higher than visibility of the irradiation pattern from the specified time to the stop time.

3. The current supplied to the light source unit is a direct current, 3. The light irradiation system according to claim 2, wherein the control unit is configured to adjust the direct current supplied to the light source unit so that a brightness of the irradiation pattern from the start time to the predetermined time is greater than a brightness of the irradiation pattern from the predetermined time to the stop time.

4. 4. The light irradiation system according to claim 3, wherein the control unit is configured to adjust the DC current supplied to the light source unit such that a value of the DC current supplied to the light source unit from the start time to the specified time is greater than a value of the DC current supplied to the light source unit from the specified time to the stop time.

5. The current supplied to the light source unit is a pulse current. The light irradiation system according to claim 2 .

6. 6. The light irradiation system according to claim 5, wherein the control unit is configured to adjust the pulse current supplied to the light source unit so that a value of the pulse current supplied to the light source unit from the start time to the specified time is greater than a value of the pulse current supplied to the light source unit from the specified time to the stop time.

7. 7. The light irradiation system according to claim 6, wherein the control unit is configured to adjust the pulse current supplied to the light source unit such that a duty ratio of the pulse current supplied to the light source unit from the start time to the specified time is smaller than a duty ratio of the pulse current supplied to the light source unit from the specified time to the stop time.

8. The light irradiation system according to claim 1 , wherein the time period from the start time to the predetermined time is within a range of 1 ms to 200 ms.

9. 1. A lighting unit configured to project a light pattern onto a road surface, comprising: The lighting unit is configured to irradiate the irradiation pattern onto the road surface such that visibility of the irradiation pattern from a start time when irradiation of the irradiation pattern is started to a predetermined time is higher than visibility of the irradiation pattern from the predetermined time to a stop time when irradiation of the irradiation pattern is stopped.

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